1. Field of the Invention
This invention relates to a check valve assembly wherein a ball is movable along a curved path of travel between a first, flow impeding position adjacent a fluid inlet and a second, flow enabling position spaced from the inlet, and wherein the second position is disposed laterally of a substantially straight fluid passageway between the fluid inlet and a fluid outlet. A housing for the assembly includes two opposed, spaced members for guiding the ball between the first position and the second position, and the configuration of the members as well as the housing walls is such that the ball is continuously cleansed of solid matter by fluid flow around the ball when the latter is in its second, flow enabling position.
2. Description of the Prior Art
A variety of check valves have been proposed in the past for permitting the flow of fluids through a conduit in a first direction, while substantially precluding flow of fluids through the same conduit in an opposite direction. Some check valves are of a "flapper" type and have a hinged valve plug or panel which is shiftable toward a fluid inlet for obstructing flow in one direction, and which is swingable to an open position spaced from the inlet for permitting flow in the opposite direction. It has been found, however, that flapper valves are not entirely satisfactory for certain applications, including instances where the flowing fluid carries solid matter or debris which can become entangled with the valve hinge or otherwise impede smooth, free action of the hinge such that the valve does not open and close within desired specifications.
Other types of check valve assemblies utilize a ball which is shiftable within a chamber of a housing between a flow impeding position adjacent a fluid inlet and a flow enabling position spaced from the fluid inlet. The ball has a diametric cross section larger than the diameter of the fluid inlet, and the housing is provided with a spherical seat for the ball adjacent the fluid inlet so that the ball and seat form a fluid resistant seal to substantially prevent fluid flow in an opposite direction from the chamber and back through the inlet.
Certain types of ball check valves have housings with an internal fluid chamber of a generally "Y" configuration. In these valves, the fluid inlet is located adjacent the juncture of two diverging passageways, and one of the passageways functions as a guiding channel for movement of the ball while the other passageway has a fluid outlet at its outermost end and serves as a fluid conduit between the inlet and outlet. Unfortunately, fluid captured in the channel for the ball is stagnant, which facilitates the collection of solid debris and other foreign matter occasionally to such a degree that the valve is rendered inoperable.
Another type of ball check valve assembly is shown in U.S. Pat. No. 3,741,243 to Deibler et al., which is assigned to the assignee of the present invention. The check valve assembly of this patent has a ball contained within a housing chamber and movable in approximately a straight line between a position adjacent the fluid inlet and a position intermediate the inlet and an outlet port. The chamber includes a bypass region of sufficient cross sectional area to permit fluid flow around the ball when the valve is in its open position. While the check valve shown in U.S. Pat. No. 3,741,243 represents a significant advance in the art due to elimination of stagnant pockets of fluid, this type of valve can satisfactorily handle fluids carrying solid matter of limited size, since the fluid flow is confined to a somewhat restricted pathway past ball guiding structure and around the surface of the ball until the fluid outlet is reached.
As can be appreciated, it would be a desirable advance in the art if a ball check valve assembly was provided wherein stagnant pockets of fluid are eliminated and the ball is guided away from a straight fluid passageway between a fluid inlet and an outlet so that the ball does not obstruct or otherwise hinder flow of fluids through the valve assembly. Moreover, the check valve housing and ball guiding structure should be configured to eliminate flutter of the ball when the latter is shifted toward a flow enabling position, since such flutter could otherwise cause turbulence in the flow and lead to cavitation.